TheBlackPearl

Are you guys talking about turning engine pistons? If you are, I'd think HSS would be just fine for that.
I love cutting with Carbide, but we do some high volume jobs with alot of material removal so it's worth it.
Sit down when you start pricing out Carbide k? :-)
I don't think I would trust a Grizzly lathe for that though, not enough repeatability there.
If you need some prototype type work done let me know, I'm ok with a lathe but I'm pretty good on a mill.
I could get one of our guys to make a program at least.

And as a rule of thumb, I leave .005-.010 for a final pass when milling, and for what I've done on the lathe .003-005 for a final has been working great.
Depending on the mat'l if you try to cut too little, it will just deflect the tooling and make a "spring pass.